Stir together sugar, flour, cocoa, baking powder, baking soda and salt in large bowl. Add eggs, milk, oil and vanilla; beat on medium speed of mixer 2 minutes. Stir in boiling water (batter will be thin). Pour batter into prepared pans or fill cups about 2/3 full with batter.

Bake 22 to 25 minutes or until wooden pick inserted in center comes out clean. Cool 10 minutes; remove from pans to wire racks. Cool completely. Frost with Chocolate Buttercream and decorate with sprinkles. We piped a little bit of the store bought frosting in a cloud shape to attach the rainbow sugar. Makes approximately 24 cupcakes.

Recipe Courtesy of Hersheys.com

Whipped Chocolate Buttercream Frosting

You will need:

2 cups (16 ounces) unsalted butter, at room temperature

5 cups powdered sugar

2 teaspoons vanilla extract

8 ounces semisweet or bittersweet chocolate, melted and cooled

Directions:

Using the wire whisk attachment of your stand mixer, or an electric mixer, whip the butter on medium-high speed for 5 minutes, stopping to scrape the bowl once or twice.

Reduce the speed to low and gradually add the powdered sugar. Once all of the powdered sugar is incorporated, increase the speed to medium-high and add the vanilla, mixing until incorporated. Add the melted chocolate and whip at medium-high speed until light and fluffy, about 2 minutes, scraping the bowl as needed to incorporate all of the chocolate.

You can store any unused buttercream in the refrigerator in an airtight container; let it come to room temperature and then give it a quick whip in the mixer before using.